M 



36 On Bowlders and Rolled Stones. 



er than the bottom of the valley, now is west of this ridge. 

 It is composed chiefly of clay slate in a vertical position, and 

 it was at top more than one hundred feet across, and twice 

 that at bottom. Through this ridge the water and gravel 

 had cut a channel nearly one hundred feet deep — I say 

 the water and gravel, for the two sides of the section are 

 rounded off in such a manner as to leave no doubt of their 

 having been thus worn. But this is not all— as this channel 

 was in the act of wearing down, it was constantly deposit- 

 ing gravel and sand on the east and opposite side from this 

 valley, on which side the ridge of rocks was nearly perpen- 

 dicular. This gravel has been spread out so as Xp be al- 

 most a thousand feet wide on the side of the ridge, and 

 nearly two hundred high on the eastern side, reaching out 

 four or five hundred feet from the ledge. The mass is 

 very nearly of a semi-circular form, and the eastern side of 

 it was deposited in that upright position, which banks of 

 sand, or sand and gravel always assume when deposited in 

 still water, thus indicating, like thousands of other similar 

 instances, that in those days there was little or no wind to 

 agitate the ocean. Since the ocean has ceased to flow up 

 this valley, the brook, a small stream, has a channel 

 through this slate ridge still deeper, at the same time re- 

 moving the gravel also through the centre of the bank 

 quite down to the solid rock at bottom. The ruins thus 

 removed, have been carried forward and deposited in the 

 pond, forming a point of laud, or rather gravel, four or five 

 bundle i feet in extent, wiien the water was forty feet deep. 

 This brook, since the sea flowed up this valley, has not 

 only deepened its bed through the centre of this bank to 

 the bottom, but it has also cut itself a channel more than 

 one hundred feet deep in a slate ledge. The appearances 

 on the two sides determine with great precision the rela- 

 tive effects of water and gravel, and of water alone. When 

 they were united, the remaining rocks below those acted by- 

 water only are all worn or rounded off, the channel is much 

 narrower, and the sides are left nearly in a vertical posi- 

 tion ; altliough the chasm is one hundred feet deep, the 

 projectina: rocks still retain in a great measure their sharp 

 edges. Now this great deposit of rounded rocks, gravel 

 and sand, must have had their present form given in this 

 short valley and as the waters returned, were brought out 



